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Tuesday, September 23, 2014

Q.
How do I keep grubs out of my rose bushes soil? I have used Bayer advanced
complete insect killer for soil and turf. Active ingredients are Imidacloprid
0.15% B-Cyfluthrin 0.05% and other ingredients 99.80%. I don’t like using poisons as there
are plenty of birds here. However, my roses end up with no roots and miniature
leaves and blossoms as they try to survive. I ran out of wood mulch and have
been using pinecones from the golf course as a temporary mulch. Could this be
the problem? I don’t want to pull up the roses and toss them. They have been
beautiful in the springs and falls of past. Every pinecone I turned over had 2
or 3 grubs under it, on top. Imagine what is down in the soil. Last year just
one rosebush had them. I dug out all the soil and replaced it. I have used this
product twice this year and still have a zillion gross grubs. Please help!!!

Q.
I have just been told that I have "Grubs" here in Las Vegas,
NV. What do I do to get rid of them?

Grubs from compost

A.
You have two approaches to controlling grubs; conventional pesticides or
organic controls. The conventional pesticides are usually much more effective
and fast in getting rid of the problem.

Organic controls are slower to work and
may not give you the same kind of control you can get with conventional
pesticides. I would suggest purchasing a conventional insecticide in granular
form and watering and in around the base of your plants.

There are several products on the market
that will give you good control. You can also use a liquid but you would applied
as a drench, diluting it as the label recommends and pouring it around the base
of the plant where the irrigation water is applied. You would lightly water
both of these products into the soil.

Do not over water or you can push the
chemical beyond the depth where the grubs are feasting. Any of the conventional
pesticides that are labeled for grub control will give you good control.
Because these grubs are immature forms of flying insects, they may be back in
future years and you will have to re-treat.

Organic
controls rely on other living organisms to give you some measure of control.

There are three posts on my blog that
refer to controlling grubs. The links should take you to these posts and you
can read more about them if it fits your particular circumstances.

Q.
I have discovered over 200 huge grubs in a 15 x 24 inch container that is about
2 ft deep. I had filled this container with a bag of garden soil from a garden
center and planted strawberry plants. Of course the plants all died, ...

Q.
I ran across an item called Grub Guard in the catalog. It contains beneficial
nematodes. Would these be the same kind of nematodes that attacked my tomatoes
last year? A. These are entirely different nematodes. These are ...

These
are the immature of one of the scarab beetles such as June beetles, metallic
June beetles, dung beetles and rose chafers which we have here. Another one
that attacks lawn grasses is the "white grub" or sometimes
just ...

Q.
My Ozark Beauty and Ogallala strawberry plants produced a few berries when
first planted and now they want to propagate. This growth is filling my raised
bed to my satisfaction. I clip them down, water and watch them
grow! Please provide your most welcome and appreciated advice.

A.
You will want to give each individual plant its own space to grow. Space plants
no closer than 1 foot apart and remove all of runners as you see them.

You can plant them further apart and
propagate your own plants from the runners but you still want them no closer
than 1 foot apart. All the rest of the runners you want to remove from the
plants or they will get overcrowded, shade themselves, give you very low
production and make it difficult to harvest.

Strawberries growing in Las Vegas in amended desert soil demonstrating good color and good health

Strawberries growing in Las Vegas soil amended with compost but showing the beginnings of iron chlorosis

The plants that you decide to keep and
spaced far enough apart will last you about three years. These are the mother
plants. So at the beginning of the third year begin to propagate new plants
from the runners of the mother plant with the idea that these new plants will
replace the mother plants at the end of the third year.

You can keep these new plants in place
by just pegging or securing the new plants in a spot by holding down the runner
and baby plant in its new location. When new roots begin to form you can cut it
from the mother plant at cool times of the year such as March or September.

You can move them in the fall when they
are young if they are not in the right place.

There
are three types of strawberries classified on the time of year they produce.
Main crop strawberries produce a single crop of fruit and then turn their
energies to the production of runners, roots and leaves.

Strawberries with damage from the vine weevil

In my opinion you run the highest risk
of not producing fruit by using main crop strawberries in our climate.
Everbearing strawberries like Ogallala and Ozark Beauty are supposed to produce
all during the spring, summer and fall months but usually tend to produce their
fruit mostly in the spring with a trickle the rest of the year.

Then there are the day neutral varieties
like Tri-Star which are supposed to produce more consistently all through the
year but usually end up producing in the spring and fall when it is cooler. So
expect to see fruit most likely in the spring months and some in the fall
months. The rest of the time expect to see runners and leaves.

Like most vegetables and fruit trees
they need at least six hours of sunlight every day. They prefer morning and
early afternoon sun. They like soils with lots of compost added to it. They
like to be mulched with straw or pine shavings such as animal bedding or even
shredded newspaper.

Generally speaking strawberries stop
producing fruit when temperatures are hot (85 to 90° F) so main crop
strawberries, kind of like tomatoes, are hit and miss in our climate. We are
better off with everbearing or day neutral types which you have.

However, yours are older varieties, very
hardy with well-established names but there are better varieties out there. We
are very limited here in what is available for home gardens so nurseries
usually stay with varieties with names that are recognized. Some people plant
all three types to improve their chances of getting some fruit.

Avoid fertilizing plants with nitrogen
fertilizers in the early spring. Wait for them to finish producing fruit in the
early summer and then fertilize them if they need it. You can tell if they need
it by looking at the leaf color and size.

Fertilizing them at the beginning of
summer you will be pushing new growth at a time when they normally don't
produce any fruit.

The biggest problems with strawberries
is iron chlorosis or yellowing leaves, keeping the soil to moist and developing
root rot, Strawberry weevils, snails, slugs, pillbugs or sow bug damage to the fruits.

Q.
We have a fertilizer tank attached to our watering system. I've had it checked and it is working, as in
past years. However, this summer most of
the plants in my perennial flower garden, yellow bells, and bougainvillea are
green but few blooms. Lantanas and purple
rubella are blooming well.

A.
Fertilizer tanks attached to an irrigation system can be a big plus for the
overall landscape quality. However there are some things you should realize
about using fertilizer tanks and fertilizer injectors. First of all plants
receiving the most water, also received the most fertilizer. When we use
fertilizer injectors it is best to have them inject fertilizer several minutes
after the cycle begins and shut down several minutes before the cycle turns
off. This gives a better fertilizer distribution to all of the plants on that
circuit and cleans the irrigation lines out of any extra fertilizer. Water
containing fertilizer sitting in irrigation lines will frequently contribute to
plugging because of algae and bacterial growth that occurs in lines that
contain water laden with fertilizer. If you don't have this luxury of flushing
the lines with clean water, you can flush the lines yourself once a month with
freshwater by turning off the injector for a few irrigations. You might want to
consider not having the fertilizer tank on all of the time but using it
periodically, perhaps once or twice a month, instead.

Air release valve for drip irrigation using a ball to close the valve

Air release valve for drip irrigation using a diaphragm to close the valve

Typically,
plants at the beginning of an irrigation line receive more than those at the
end of an irrigation line. You can eliminate some of this problem by installing
an air release valve somewhere along the irrigation line. This allows trapped
air to exit the irrigation line and speeds the delivery of water and fertilizer
along the line to all of the plants. Otherwise air can be pushed ahead of the
water and slow the delivery of water and fertilizer along the length of the
irrigation line.

The
type of fertilizer you are using may impact the plants as well. Try to use
general purpose fertilizers with the ratio of 3-1-2 or 4-1-2
(nitrogen-phosphorus-potassium). We usually want to apply very low levels of
phosphorus if we are feeding plants continually. Phosphorus can build up in the
soil and become a problem if too much is applied. If particular plants require
higher amounts of phosphorus than these plants can be sprayed on their foliage
with a high phosphorus fertilizer or the fertilizer can be applied at their
base and watered in.

From
the sound of your email, you may be applying too much nitrogen. I would tend to
use your injector once or twice a month if it is on continuously now. Let me
know how this works for you.

Q. I have a mimosa silk tree that
is covered in ants. I assume they are herding aphids infesting the
leaves. I want to use a systemic ground-soak poison. Star Nursery has
a product to be used annually. I will use it on my shade trees
(eucalyptus, California Pepper, Texas Mountain Laurel, Chitalpa) if you
say a systemic treatment is appropriate.

Can I also use it
on my fruit trees (peach, nectarine, apricot, fig, Pink lady apple) and
grape vines? My pomegranate trees are not as infested with leaf footed
hoppers as in the past, but they are there. The kid at Star told me to
just stop using the poison a few weeks before harvest, but that makes no sense
to me, with an annual-use product.

I don't plan to use a systemic in
my garden.

A. The product that was recommended to you was probably this
one. Here is a posting on my blog regarding its use. I am never a big fan in using any kind of systemic pesticide where there are food crops. Hope this helps.

Q.
The new growth on my citrus trees (Lemon, oranges, and grapefruit) are starting
to curl up at they grow. Attached are a
few pictures. They are watered every
three days, 12 gals per watering. I fed
them every six weeks starting at the end of Feb with a balanced citrus
fertilizer.When I had a yellowing leaf
problem I gave them iron and spayed the leaves with Epsom salt. Last feeding was Sept 1. I checked some of your past blogs but could
not find anything that mentioned this kind of problem. Any thoughts or suggestions.

A.
In our climate this is nothing to be concerned about. We don't have a lot of
citrus here so many of the insects that might cause curling or cupping of
leaves are not commonly present here.

Most likely what you are seeing is
growth of citrus in response to our heat. I think the outer edges of the leaves
become damaged or their growth slows compared to the rest of the leaf and new
growth begins to distort.

You should not see this in new growth in
the spring. In other parts of the country where citrus is more common this
could be an insect related problem or an irrigation problem. In our case here
and because it's happening on so many of your citrus it is most likely heat
related and a temporary problem.

Q.
I am very excited as I am about to plant 4 pomegranates - Ambrosia, Purple
Heart, Hotuni-zigar, and Sirenvyi.

Ambrosia pomegranate

A.
Out of your four pomegranates I only have experience with Ambrosia. It is one
of the earliest pomegranates but to be honest I am not a big fan of its flavor
or appearance and neither were any of the chefs that I introduced it to. It did
seem to improve a little bit in flavor after sitting in the refrigerator for a
couple of weeks after harvest.Perhaps some of the other readers of this blog might be able to comment on your other selections.

Q. I'd like to plant a few manageable nitrogen fixing plants and go about fertilization without chemicals, if possible. Can you recommend any?

A. There is a misunderstanding in the general horticulture community about what nitrogen fixing plants can and can't do. Nitrogen fixing plants, those plants which can take nitrogen from the air and convert it to nitrogen that a plant can use, do not produce enough nitrogen to support other plants nutritionally that most gardeners might be comfortable with.

If you are looking for a trickle of nitrogen to your trees, then perhaps selecting the right nitrogen fixing plant might provide some benefit to your trees. But most nitrogen fixing crops or plants actually require additional applications of nitrogen to perform at its higher levels of production.

Nitrogen fixing plants, in my opinion, give the greatest benefit in what we call it green manure crop. These are plants that are grown to a certain stage of maturity and then recycled back into the soil. These plants take nitrogen from the air and also nitrogen from the soil and put it into a form that can slowly decompose.

The decomposition of nitrogen fixing plants in soils allow the nitrogen that they have fixed from the air and the soil and converted into forms that slowly release this fertilizer over time. So another words, they take nitrogen that would otherwise might be lost in the environment and give crops a better chance of utilizing it.

If you are a permaculturist or a gardener who puts more value into sustainability than the appearance or total production of their garden, then you might be able to appreciate what some of these nitrogen fixing plants can do for trees.

But if you are expecting to have a level of production and visual quality of fruit that you could buy from a grocery store or a farmers market, you will probably be disappointed. This does not mean that the fruit will not taste good or it will have a decreased level of nutrients.

In fact, the opposite might occur in some fruits but you should not expect the level of production to compete with neighbors who are growing organically or conventionally.

I have attached a link from New Mexico State University that talks a little bit about this.

Q. Attached is a picture of my Kumquat tree. I apologize for
the picture as there is a lot of other shrubs around the tree making it hard to
get a good picture of the tree. It has been planted for approximately
three years and is 5-6 feet tall. The picture is facing North. Just
within the last year we have had very little fruit whereas prior to that the
tree was ample with fruit. There has been no change to the water schedule
(3 days per week for 45 min. each). The tree appears to be healthy, just
no fruit.

Readers kumquat tree

The only difference I can think of is that in previous years I
covered the tree whenever the temperature was below freezing; however, this
past year I only covered it when the temperature fell to the upper 20s. I
think this tree is able to withstand these types of temperatures though.
Any advice you might have would be greatly appreciated.

A.
Kumquat is a very winter hardy citrus and can survive most winter temperatures
here without any problems provided it is in a sheltered spot. It is considered
one of the more cold tolerant of the citrus. The key question you have to ask
yourself is whether it produced any flowers are not this year.

The
major reasons for fruit drop are temperature and irrigation problems. If we
have freezing temperatures or if the plants become water stressed from not
enough water, they tend to drop fruit if it was produced or even flowers.
Flower buds and fruits are much less hardy to freezing temperatures than the
plant itself.

Kumquat
may produce fruit all through the year but tend to produce fruit in the spring
and fall months and through the winter. If it does get some winter damage, you
would've seen die back. The plant will regrow to the height it was before it
had damage with very few flowers. Once it reestablishes the size of had before,
it will then begin to flower again more profusely and produce fruit. If there
were some spring freezes the flower buds would be killed before anything else
would show any damage. This would tend to minimize fruit production. If the
plant receives a lot of fertilizer, particularly nitrogen, it may tend to put
on new growth with few flowers and of course very little if any fruit.

A.
I am looking at your picture now of the peach leaf. It was hard to see what the
problem might be with only one picture and that picture was low resolution.

What I saw was one leaf inside the canopy in some shade with some black spots
developing on the leaf margins. I couldn't be certain but it looked like there
was a yellow halo around the black spots on the margins.

I don't know if this
is typical of all the leaves or just the leaves in the shade. For me there were
two possibilities; irrigation or a disease called shot hole fungus or Coryneum
Blight.

If it was over the entire canopy and it involves leaves in full
sunlight then I would tend to think it was irrigation related. It usually
occurs if the tree is not getting enough water at the time of an irrigation or
if you waited too long between irrigations. If the tree has gotten considerably
larger in the last two years than I would add any emitter or two to the irrigation
of the tree. I would also mulch the surface of the soil to conserve water and
reduce water stress.

If
this is Coryneum blight then you would spray the tree with a copper-based
fungicide such as Bordeaux mixture immediately when the leaves fall from the
tree this early winter. You would follow up with the spray in the spring as the
leaves are coming out and new growth is emerging but after blooming has
finished.

LAS VEGAS, Nev. – The Conservation District of
Southern Nevada invites the community to attend the third Annual Solarbration solar
festival which will be held Saturday, October 11, 2014 at the University of
Nevada Cooperative Extension’s Lifelong Learning Center from noon to 4 p.m. The
purpose of the festival is to blend art, technology and outreach to promote
renewable energy, inspire conservation, and support sustainable
communities.

The Solarbration festival will offer the
community the opportunity to enjoy solar-powered art, live music, food and
fun.Plus, there will be solar
demonstrations and the latest information on sustainable energy.

“We
promise to deliver a fun-filled family event that will be a one-stop location
for everything related to going solar,” said Jon Wardlaw, Commission Chairman
of the Conservation District of Southern Nevada.“We will have all the latest information
regarding energy rebates, tax credits, solar financing, and lots of hands-on
activities for all ages.”

Like last year, the event will be “bike friendly” and
promises to be even more fun and activity-packed than last year. The Lifelong
Learning Center is located at 8050 Paradise Road, Las Vegas, Nev. (I-215 and
Windmill Lane) right near the Clark County 215 trail.Bike clubs are encouraged to make a ride out
of the event.

Solar Village

You won’t want to miss The Solar
Village where visitors will have a chance to meet over 35 exhibitors, with
selected presentations on solar living, electric cars and more plus have the
opportunity to get answers to questions about solar energy, and find out how
they can install solar on their home or business.

Plus there will be hands-on fun
activities for children.There will be
solar art projects, fun in the sun games and make-and-take solar nightlights to
name a few of the many and varied activities.And the Food Trucks and live bands will be there so the evening will be
complete with great food as well.

Whether you are looking for
information on solar financing, the Solar Generations rebate program, Federal
rebates, energy efficient home improvements, or energy star appliances, the
Solar Festival will be your one-stop resource center. The wide range of
exhibitors will include solar and renewable energy companies, green home
builders, sustainable home products, and hybrid and electric vehicles.

The event will be free
to the public and all ages are welcome.

Proceeds
will go to commission a solar powered public art project to be enjoyed as our
community continues to celebrate solar energy.For more information visit http://www.cdsn.org/events/solarbration.html or like the Solar Festival – Las Vegas page on Facebook.

A.Amaryllis is a perennial flowering plant that comes from an underground bulb, much like a tulip.At 4 feet tall,yours is a large one. The size may vary with a variety and light exposure. If
they are not getting enough light the leaves will be very succulent. With
adequate light believes should be leathery and more durable. Amaryllis is a fun plant to grow in the desert provided you amend the soil with compost and cover the soil surrounding it with an organic mulch such as wood chips that decompose and continue to improve the soil.Make sure you keep it away from late afternoon sun.

You have your amaryllis in good exposure
it sounds like with it in the East side with some filtered light during part of
the day. Amaryllis does well with half-day sunlight. As you've already
expressed I'm sure that you amended your soil with compost the time of planting
and mulched the bulbs.

Sometimes the flowers need staking
because they can get a little top-heavy. They will die back at the first frost.
At this time feel free to cut them back to the ground. Cover the bulbs with 4
to 6 inches of wood mulch through the coldest part of the winter.

When all danger of frost has passed go
ahead and uncover them and let them warm up. I would fertilize lightly once a
month.

You can buy Amaryllis in many of the stores like Home Depot and Lowe's while they are in bloom. Enjoy them in your home while they are blooming and then transfer them outside and plant them in the ground or in a container.
And planting them in the correct soil are both important with this plant. If you plant them in shade you might be disappointed when they don't bloom the way they are supposed to. They need light but they should receive light during the cooler parts of the day and protected from sunlight when it is very hot. This means the Eastern or northern exposures are best as long as they avoid the late afternoon sun. Planting under trees that provide filtered light, but not dense shade, will also work.
Soil improvement is extremely important. When you are planting make sure you add at least 50% compost to a desert soil. Soil amendments decides compost should include all meal or a high phosphorus fertilizer at the time of planting and mixed with the compost/soil mixture. You might need to stake the flower stalk at the time of planting if you fear wind damage. Use a thin bamboo stake and green nursery tape.
As with any flowering plants in the garden, fertilize this plant with a good fertilizer for flowering like you might use for roses or gardenias. Fertilize them once a month lightly during their growing season.
Amaryllis can also be used as a cut flower inside the home.More information on Amaryllis from the National Arboretum You will have to adapt this information to our climate.

Welcome to Xtremehorticulture

Home. My home base is Las Vegas, Nevada, in the Eastern Mojave Desert. This blog focuses on horticulture in Deserts.

Me. Desert Horticulture is very different from horticulture in wet climates. Very few people talk about it. This blog focuses on it. My experience in horticulture span over 50 years; time as an applied academic and now working as a consultant. This blog shares my experience and advice in Desert Horticulture. Work in Northern, East and Southern Africa, Western and Central Asia and the Middle East have expanded my views on Desert Horticulture.

Questions. I reply to questions sent to me as quickly as possible. Please include pictures. It helps. Unless questions are confidential, I post them on this blog if they add new information.